Embodiments of the device and method discussed herein relate to a system and method for manufacturing intracorporeal devices used to replace, strengthen, or bypass body channels or lumens of patients; in particular, those channels or lumens that have been affected by conditions such as abdominal aortic aneurysms.
Existing methods of treating abdominal aortic aneurysms include invasive surgical methods with grafts used to replace the diseased portion of the artery. Although improvements in surgical and anesthetic techniques have reduced perioperative and postoperative morbidity and mortality, significant risks associated with surgical repair (including myocardial infarction and other complications related to coronary artery disease) still remain.
Due to the inherent hazards and complexities of such surgical procedures, various attempts have been made to develop alternative repair methods that involve the endovascular deployment of grafts within aortic aneurysms. One such method is the non-invasive technique of percutaneous delivery of grafts and stent-grafts by a catheter-based system. Such a method is described by Lawrence, Jr. et al. in “Percutaneous Endovascular Graft: Experimental Evaluation”, Radiology (1987). Lawrence et al. describe therein the use of a Gianturco stent as disclosed in U.S. Pat. No. 4,580,568 to Gianturco. The stent is used to position a Dacron® fabric graft within the vessel. The Dacron® graft is compressed within the catheter and then deployed within the vessel to be treated.
A similar procedure is described by Mirich et al. in “Percutaneously Placed Endovascular Grafts for Aortic Aneurysms. Feasibility Study,” Radiology (1989). Mirich et al. describe therein a self-expanding metallic structure covered by a nylon fabric, the structure being anchored by barbs at the proximal and distal ends.
An improvement to percutaneously delivered grafts and stent-grafts results from the use of materials such as expanded polytetrafluoroethylene (ePTFE) for a graft body. This material, and others like it, have clinically beneficial properties. However, manufacturing a graft from ePTFE can be difficult and expensive. For example, it is difficult to bond ePTFE with conventional methods such as adhesives, etc. In addition, depending on the type of ePTFE, the material can exhibit anisotropic behavior. Grafts are generally deployed in arterial systems whose environments are dynamic and which subject the devices to significant flexing and changing fluid pressure flow. Stresses are generated that are cyclic and potentially destructive to interface points of grafts, particularly interface between soft and relatively hard or high strength materials.
What has been needed is a method and device for manufacturing intracorporeal devices used to replace, strengthen or bypass body channels or lumens of a patient from ePTFE and similar materials which is reliable, efficient and cost effective.